Vehicle headlight



Get 9, 1928,

'w. H. WOOD VEHICLE HEADLIGHT Filed Feb. 2, 1927 Pm, A

VI'IJUJFIV'JJ WMULEAM Ho W000 lNvENToQ M ATTORNEYS Patented Oct. 9, 1928.

- UNITED I s r TEs WILLIAM H. WOOD, OF SOUTH EUCLID, OHIO.

VEHICLE HEADLIGHT.

v Application filed February 2, 1927. Serial No. 165,253.

' This invention relates to headlights for vehicles and has for its object the provision of a new and improved construction which shall afford the necessary faint illumination above the horizontal axis of the headlight and directly in front thereof while avoiding illumination at distances slightly to one side thereof; the provision of a headlight construction which shall produce the desired dis- 1 tribution or pattern of light rays by the use of a'uniformly fluted lens and without requiring special patterning of such lens at different points; the provision of a headlight which shall produce the desired light pattern .15 by the aid of a lens of rolled glass; while further objects and advantages of the invention will become apparent as the description pro ceeds.

- In the drawings accompanying and forming a part of this application I have illustrated certain forms of headlight and certain diagrams explanatory of my inventive idea. Fig. 1 is a vertical, axial, sectional view through the essential parts of a headlight em- 23 bodying my improvements; Fig. 2 is a front elevation of the reflector shown in Fig. 1;

Figs; 3 and 4 are front elevations of modified forms of reflector; Fig. 5 is a front elevation of a portion of rolled glass showing the mode of cutting a lens therefrom; Fig. 6 is a horizon sectional view of the lens taken, on line 66 of Fig. 1"; Fig. 7 is a diagram of the light pattern produced by the naked reflector; Fig. 8 illustrates the light pattern produced by the combined effect of the reflectorand lens.

In defining and analyzing headlights it is customary to refer to certain points identified by letter and .spaced'at known angular positions with reference to the headlight axis -10 which axis is assumed to be horizontal. These conventional points are illustrated in Figs. 7 \g1d8 hereof, and are identified as follows:

Point Location I Intensity a. Axially in front econ-24,000 r. c. b 1 below a 10,00050,000 f. c.

c 1 above a 8002,400 f. c. d 436 laterally of c to the left only 200 f. c. max. 1%-..- 1% below a and 3 laterally 5,000 f. 0. minimum. q.- 3 below z and 6 laterally 2,000 f. 0. minimum.

The quantities given in the third column bulb having a filament 4 located on or near the first of the above named objects may conveniently be expressed as controlling the cl light independent of the 0 light which is the most difiicult thing ,of all todo, while maintaining the intensities between the prescribed limits in other-parts of the field.

' My invention consists in performing this operation by the combined use of a reflector and lens, the reflector being so shaped as to cast a narrow beam of light above the horizontal exactly at the center of the field, and the lens adding an amount of spread sufficient to smooth up the irregularities in the field but without spreading the 0 light across the al point. This result may be obtained with any one of several different reflector con structions. That shown in Figs. 1 and 2 compr ses paraboloid portions 1-1 coaxial with the line tz-a and having a focal point at 7 combined with other portions 2-2 above apd below the same so arranged that the normal to every portion thereof shall intersect the vertical axial plane somewhere below the axis. In addition to the two types of regions above described I provide a third typeof 0 region indicated at 3-3, wherein over one or more comparatively small areas the normals intersect the vertical axial plane above the axis. With this reflector I'employ a lamp axis arc and at or near the focalpoint f. I As a result of the construction heretofore described, the paraboloid portions 11 cast a concentrated bundle of light rays .22 substantially parallel to :the axis illuminating the field m shown-in Fig. 7 the-portions 2-2 cast their beams downwardly and divergently as shown at -2 illuminating the field-z] shown in Fig. 7; while the'portion or portions 33 produce a narrow beam 2 (Figs. 1 and 7 lying at above the axis. These three fields are preferably arranged to overlap vertically to some degree as indicated in Fig. 7 but 'made too narrow laterally for comfortable driving or legal acceptance. In front of said reflector I locate a trans parent glass lens 5having vertical flutes .6, preferably uniformly distributed over the surfaces of the same and having what is a known in the art as aspread of not over 10 and preferably somewhat less, for example about 8. This expression means that such a lens, when placed in front of a narrow beam of parallel rays will expand the same 4 upon each side of the original band or 8 in all. 110

' field below the axis.

comes necessary to preserve the same configu-.

It is neces- The result of using such a lens wit-hsuch a reflector is illustrated in Fig. 8. The narrow beam at a is drawn laterally but terminates short of the point (i, the concentrated beam at is drawn laterally into a distance beam of convenient dimensions, while the portion 1 is expanded to cover the remainder of the by rolling the glass in sheets and cutting circular sections therefrom as shown in Fig. 5.

When a double. filament lamp is used asillustrated in Fig. 1 it is the main or driving filament which is located at fan I have described. The other filament is located above the axis, and in most cases'at or near the focalQplane. VVhen the filament 10 is used the entire light pattern is depressed (the portions of the reflector in front ofthe focal plane are assumed to have been modifledwith this in view atleast those portionswhich fall Within the regions 22) and upon this depression of thelightpattern it no longer be ration of the top of the beam. sary, however, when a double filament lamp is used, that the region or regions 3 be located in the rear of the focal plane lest the use of the upper filament should cause a still more pronounced upward deflection of the beam 2;

. I with a single filament lamp it is permissible for some or all of this region 3 to lie in front of the focal plane.

In the form of reflector shown in Fig. 8

I I have changed the shape of the portionsl used therewith.

It will be understood that I mention 8 only because of the fact that this spreads the light' less than serves to cover the d point, but I do not restrict myself absolutely thereto.

Such a lens can be made In the form of reflector shown Having thus described my invention what I claim is:

1. In a headlight, the combination with a light source, of a reflector having portions approximating a paraboloid whose focal point is located near said light source to pro-' duce a concentrateddistance beam, and hav- 'ing one or more additional regions of com-" paratively small area whose normals intersect the-vertical axial plane at a point above said light source to produce a narrow beam above the axis, the remaining portions of. said reflector having their normals passing below the level of said light source so that a spreading, downwardly deflected illumination is produced, and a lens in front of said reflector having its surface covered uniformly by vertical flutes having an angular sprea dingefl'ect of not over ten degrees, the width of such narrow beam being such as not to be spread laterally by said lens more than four and one-half degrees from the center line.

2. In a headlight the combination with a light source, of a reflector having portions ap proximating a paraboloid whose focal point is located near said light source to produce a concentrated distance beam, all other regions of said reflector with one exception having their normals falling below said light source whereby a spreading, downwardly deflected illumination is produced, said re-. maining region comprising one or more small areas located behind the focal plane and having its normals passing above said light source to produce a narrow beam above the axis, and

a lens in front of said reflector having its surface covered uniformly by vertical flutes having an angular spreadin'geflect of not over ten degrees, the width of such narrow beam being such as not to be spread laterally by said lens more than fourand one-half degrees from the center line. I

3. The improvement in vehicle headlights substantially as described and for the purpose set forth;

In testimony whereof'I hereunto affix my signature.

WILLIAM H. wo'on. 

